The two formal complaints were investigated and no evidence of harassment or bullying was found.

A former staff member alleges Ms Barry's staff were "terrified" of her, and that she "belittled" their work. Ms Barry told Newshub she denies all the allegations.

"I disagree entirely. I am not toxic."

An email to National MPs was leaked to media on Tuesday, giving the caucus talking points on bullying, including: "Parliament's a robust environment and it's demanding."

Ms Barry was also accused of using Parliament staff for party work, a claim she staunchly refutes.

"I never ask parliamentary staff to do party work. I've been a Member of Parliament for more than seven years, and I definitely understand the distinction."

However Newshub has seen an email from Ms Barry instructing a ministerial staff member to work on a letter to National Party members. The email was sent during a work day to a parliamentary email address.

National refused to discuss the email without a seeing a copy of it. Newshub had agreed with its source not to share the email.

Electoral lawyer Andrew Geddis says it appears to be a breach.

"When you have an email like this sent during work time, it looks very much like they are being asked to do it on the taxpayer dollar - and that's what they are not allowed to do."

But Ms Barry stands by her denials, and says it's hard dealing with anonymous claims.